Material and process for applying gelatin coating to surfaces



Jan..22, 1935. H. NEUMANN 1,989,017

MATERIAL AND PROCESS FOR APPLYING GELATIN COATING TO SURFACES Filed July 27, 1929 Gelaflne STarch 4 ar an sug eez rine l NVENTOR A eflry Newman/1 a ATTORNEY Patented Jan. 22, 1935 MATERIAL AND PROCESS FOR APPLYING GELATIN COATING T SURFACES Henry Nenmann, New York, N. Y. I Application July 21, 1929, Serial No. 381,527

2 Claims. (on. 91-68) My invention relates to planographic printing and particularly to printing of the type employing a gelatin'coated surface, such as that used in cello-type printing. It is essential in printing with a gelatin covered surface thatthe thicll ess of the gelatin be uniform or be evenly distributed throughout the entire surface. Where the thickness of gelatin is uneven as in processes now in use, wherein the gelatin coating is applied directly to the plate, the resulting print is not perfect due to the unequal hygroscopic action of the varying thickness of the gelatin.

An object of my invention is to provide a process whereby the difficulties and disadvantages of the uneven thickness of gelatin are reduced to a minimum, the gelatin coating resulting from my process being for all practical purposes of even thickness throughout.

Another object of my invention is to simplify and facilitate the coating of the plate with the even thickness of gelatin and to this end I provide a cheap sheet material from which a gelatin coating of even thickness may be readily transferred 2:; and caused to permanently adhere to the zinc or other plate used in the gelatin printing art.

A further object of the invention is to provide a process of the character described which shall be highly eillcient and simple and inexpensive to so carry out, and to provide further a material of the character described which small be simple and cheap to manufacture and practical and eflicient to a high degree.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the process and various steps in carrying same out, and the features of construction, combinations of elements and arrangement of parts which will be exemplified in the following description and of which the scope of application will be indicated in the appended claims.

In the accompanying drawing in which is shown one of the various possible illustrative embodiments of this invention,

Fig. 1 is a vertical, elevational view showing sheet material made in accordance with the invention; and

Figs. 2 and 3 are per p ctive views illustrating 60 how the gelatin coating is transferred from the sheet material to the plate.

In accordance with my process, I first prepare abackingconsistingofathinsheetofmaterial such as paper to which I apply a thin coating of a. solution of starch and sugar or like solution by brush, sponge or in any other suitable manner. The paper is then allowed to dry. I then coat the backing sheet so prepared with the gelatin layer. This coating is preferably applied as follows: The

facing upward, and squeegeed down into firm contact with the level surface. The molten gelatin is then poured in the center of the sheet and gradually worked out to the edges. This gelatin, after 19 a period of time depending upon the temperature of the coating room, then sets, leaving a practically uniformly thick coat of gelatin. From the sheet material thus prepared, the gelatin coating of even thickness may be transferred to the zinc or other plate in the manner hereinafter described.

Wherethe transfer from the sheet material to the plate is made immediately, I preferably lift the sheet material from-its support by hold- 20 ing it at two adjacent corners and carry it over to the zinc or other plate, which should be dry. It is then held above the plate, the free lower edge of the sheet contacting the near edge of the plate and the hand lowered gradually until the entire gelatinized surface has been brought into contact with the plate. The gelatin coating adheres to the zinc plateand the paper backing may then be readily stripped by hand from the unexposed moist surface of the gelatin layer, leaving the zinc plate with a practically even thickness of gelatin thereon. As will be readily understood, the ready stripping of the paper backing is made possible by reason of the moistened slippery surface afforded by the starch and sugar layer. The transfer of the gelatin coating from the sheet material to the zinc plate is clearly illustrated in Figs. 2 and 3 of the drawing. The procedure above described is particularly adapted for small plates. weight of the gelatin makes hand manipulation of the sheet impractical. A wooden roller or other suitable device is therefore used in moving the'gelatin coated sheet to the plate, the sheet being supported by said roller at about its 4 mid-width with the gelatin coating on the outside and the ends of the sheet The sheet may then be gradually rolled off onto the plate by contacting the outer gelatinized surface of one end portion of the sheet with one end of 50 the plate, and moving the roller toward the other end of the plate. Because of its size, the plate is preferably first wetted with water. To prevent formation of air bubbles, the sheet may be squeegeed from the-center towards the edges,

For larger plates, the 40 the plate then set on end to allow the excess -gelatin printing art. In using the same, the sheet and plate, or other receiving support are first both wetted with water. The sheet is then placed on the plate in the same manner as above described and preferably made to adhere uniformly to the plate by squeegeeing. The wetting of the sheet dissolves the starch and sugar layer resulting in a wet, slippery surface which permits the paper backing to be easily stripped in the manner above described. 3

Briefly described, a dominant feature of the invention is that the gelatin coating is not applied directly to the zinc or other plate but instead to a thin sheet backing of paper which can be gotten in almost perfectly smooth condition and of even thickness and which may be supported on a perfectly level plate; thus making possible an even thickness of gelatin.

For processes requiring silver in the gelatin,

v the silver emulsions may'*befirst incorporated in the gelatin and then the sheet backing coated therewith as above described.

For the pigment process of photography where the prints are-made with transparent celluloid,

thegelatimcoatingmay be transferred from the sheet material to a celluloid base and then sensitized and printed in the usual way.

Apart from the application of my sheet material with the gelatin coating to the printing art, it will be readily understood that the same may be applied for many other purposes where an even thickness of gelatin is essential. For example, the gelatin coating may be transferred to canvas backings or other supports for making motion picture screens or other articles. For

such other purposes, the gelatin will be made to contain such elements as are. necessary, as for example, metallic powders where motion picture screens are to be made.

In the foregoing description the process and article have been described with reference to the coating of a plate with the gelatin layer. It will be understood, of course, that the invention is equally'applicable to the coating of any surface, Whether metallic or a flexible sheet, and the term plate as used herein and in the appended claims is intended to mean and include any surface which receives the gelatin coating.

It will thus be seen that I have provided an article and method in which the several objects of this invention are achieved and which are well adapted to meet the conditions of practical use.

its various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth, or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention I claim as new and desire to secure by Letters Patent:

As an article of manufacture, a sheet having a coa ingot substance containing starch and sugar, and a layer of gelatin on said coating.

2. The method of applying a gelatin coating ,to a plate consisting in coating a sheet of porous sugar and render the'coating non-binding, andthen stripping the sheet to leave the gelatin layer on said plate.

HENRY NEUMANN. 

